Hi all,

I’m setting up Unraid for the first time and I’m currently running Unraid 7.2.4.
I’d appreciate some guidance on the best configuration for an SSD-only array, with a focus on maximizing usable capacity while still having single‑disk redundancy.

My available drives:

• 2 × SSD – 1.92 TB

• 2 × SSD – 1 TB

• 1 × SSD – 750 GB

• Cache drive: 1 × NVMe – 256 GB

Goals / requirements:

• Protection against failure of a single drive

• Maximize usable storage capacity

• Relatively light usage:

  • One or more shared folders for general file storage

  • A few lightweight Docker containers (nothing heavy)

• No VMs planned at this stage

Questions:

1. What would be the recommended parity + data drive layout with mixed‑size SSDs like this?

2. Is it better to:

   • Use one of the 1.92 TB drives as parity and the rest as data?

   • Or consider a different approach to get better balance/capacity?

3. Any SSD‑specific settings or best practices I should be aware of (TRIM, cache settings, mover behavior, etc.)?

4. Does this setup make sense long‑term, or would you recommend a different structure given my use case?

This is my first Unraid build, so I’m trying to start off on the right foot 😊
Thanks in advance for any advice or real‑world experience you can share!

SSDs in the parity array cannot be trimmed. You can have multiple multidisk zfs or btrfs pools outside the array. The Unraid parity array is not required. All pools are part of user shares.

52 minutes ago, trurl said:

SSDs in the parity array cannot be trimmed. You can have multiple multidisk zfs or btrfs pools outside the array. The Unraid parity array is not required. All pools are part of user shares.

Thanks, Does a Btrfs pool support single‑disk fault tolerance or any form of redundancy?

https://docs.unraid.net/unraid-os/using-unraid-to/manage-storage/file-systems/

1 hour ago, eldangab said:

Thanks, Does a Btrfs pool support single‑disk fault tolerance or any form of redundancy?

No.

There is no fault tolerance with Unraid for any sort of single disk pool - you need to go multi-disk for that. A single disk btrfs pool can only report which files are corrupt - it cannot repair them.

13 minutes ago, itimpi said:

No.

There is no fault tolerance with Unraid for any sort of single disk pool - you need to go multi-disk for that. A single disk btrfs pool can only report which files are corrupt - it cannot repair them.

Thanks, my wording was problematic.

I'm planning to use 5 disks.

Unraid array is great for mixing different size drives, but it's designed for HDDs, SSDs will have no trim if you use that.

You can use multiple pools by pairing matched sized drives but you're gonna lose a lot to protection.

So you have to choose what matters most, optimal space usage but suboptimal performance and potentially faster wear by using them as array or losing a lot of capacity and dealing with separate volumes with them in pools.

Edited April 26Apr 26 by Kilrah